This invention relates to control systems for marine vessels. More particularly, the invention relates to electronic control systems for marine vessels having a plurality of engines and/or a plurality of control stations.
Marine vessels often include a plurality of engines, such as a port engine and a starboard engine, for example. Such vessels also include a transmission associated with each engine (i.e., a port transmission and starboard transmission). An engine/transmission pair is commonly known as a xe2x80x9cpower train.xe2x80x9d Such vessels typically include a plurality of control mechanisms, such as control arms or levers, via which an operator of the vessel can control the several power trains. It is common for a separate control arm to be provided for each power train. Thus, the operator of such a vessel can control the throttle of a selected engine and the shift position of the transmission associated with that engine via an associated control mechanism.
Under certain circumstances, an operator might wish to control each of a plurality of power trains individually (so that the operator can quickly turn the vessel about, for example). Under other circumstances, however, the operator might wish to synchronize control of the power trains, that is, to keep both engines at the same throttle and both transmissions at the same shift position.
To accomplish this synchronized control, the operator is often forced to try to synchronize the control mechanisms manually, that is, to try to keep both control levers in the same location relative to one another with the expectation that the engines and transmissions will, therefore, be synchronized. As this approach is cumbersome and inherently inaccurate, systems and methods have been developed previously to enable an operator to control the throttle of a plurality of engines using a single lever. Such systems typically couple a single, master control lever to a plurality of engines, so that when the operator varies the position of the master control lever, the throttle of each of the plurality of engines varies accordingly.
Such systems usually do not also provide synchronized control of the transmissions, however, and usually disengage when the operator returns the control lever to the neutral position. Additionally, the inventors know of no system whereby a operator of a marine vessel can control both throttle and shift position for each of a plurality of power trains from a single control lever. It would be advantageous to operators and manufacturers of marine vessels, therefore, if there were provided systems and methods for controlling a plurality of power trains via a single control lever.
It is well known that engine parts and other parts of a marine vessel""s control system wear due to ordinary use or misuse. It is also well known that, as these parts wear out, the responsiveness and sensitivity of the system degrades such that, over time, the operator will sense a change in system performance. To minimize the effects of such degradation, it would be advantageous to operators of such systems if the systems were automatically tune, in a manner transparent to the operator, so that the changes in system performance due to degradation of system components would be less noticeable.
Though some marine vessels have more than one control station, only one control station can control the operation of the vessel at any given time. Therefore, such vessels typically provide a capability that enables the operator of the vessel to transfer control from one station to another. Sometimes, however, the control transfer process can be initiated without the operator""s knowledge or consent. For example, children playing with a control station that is not currently in control of the vessel might inadvertently transfer control to that control station without the operator""s knowledge. Obviously, such an unauthorized transfer of control could be dangerous. It would be advantageous, therefore, if systems and methods were provided to prevent such unauthorized transfers of control between control stations.
A control lever typically permits a range of throttle from full forward, through neutral, to full reverse. As the operator moves the control lever through its operational range, the throttle varies accordingly. Sometimes, however, such as when the operator is docking the vessel, the operator would like more sensitivity from the control handle. That is, the operator would like to be able to move the control lever a greater distance without increasing the throttle. Moreover, different operators prefer different sensitivities under such circumstances. It would be advantageous, therefore, if systems and methods were provided whereby an operator could dynamically program the vessel""s control system so that the control lever""s operating range could be varied from a first range of throttle to a second, user-defined range of throttle for the same operating range of the control lever.
Typically, a marine vessel includes the capability for the operator to throttle the engine at a predefined forward idle speed and a reverse idle speed (generically, a gear idle speed). That is, for each of the one or more engines that the vessel includes, the throttle is set to a predefined throttle value whenever the control handle is moved into a predefined gear idle position. Under certain circumstances, however, an operator might wish to vary the gear throttle speed, that is, to operate the vessel at an alternate gear idle throttle speed. Moreover, different operators might wish to use different alternate gear throttle speeds. It would be advantageous, therefore, if systems and methods were provided that enable an operator to program alternate, user-selectable gear idle throttle values.
The present invention satisfies these needs in the art by providing electronic control systems for marine vessels having one or more engines, and a transmission associated with each engine. A control system according to the invention can include a control arm and arm position means for providing an electrical signal that represents a position of the control arm within its operating range.
The system includes one or more electronic control units (ECUs). Each ECU is electro-mechanically coupled to an engine and transmission. Each ECU is coupled to a communications link, via which the ECUs can pass messages to one another. Tachometric data is passed directly from the engine to the ECU.
According to an aspect of the invention, an operator can vary the neutral idle rate from the manufacturer-provided default by entering a xe2x80x9cneutral idle warmupxe2x80x9d mode. To enter neutral idle warmup mode, the operator moves the control arm into a neutral position, and inputs a neutral command to the control system via a command input device. The control system then enters neutral throttle warmup mode. Thereafter, the control lever can be used to vary the idle throttle rate (i.e., increase or decrease the throttle of the associated engine without engaging the associated transmission).
According to another aspect of the invention, the operator can initiate transfer of control from one control station to another regardless of the current throttle rate or shift position. To initiate a station transfer, the operator enters a select command at the station to which control is to be transferred (the transferee station). Then, if, within a certain amount of time, the operator matches (approximately) the lever position at the transferee station to the position of the control lever at the transferring station, transfer of control occurs. According to this aspect of the invention, the control system can be configured to require the operator to enter a station protect sequence in order to transfer control from the transferring station to the transferee station. In station protect mode, the operator is required to enter a sequence of commands from the transferee station, and to match the control levers at the transferee station to within a predefined tolerance of the lever positions at the transferring station within a short timeout period after the sequence is entered.
Typically, the default idle throttle rates are set by the engine""s manufacturer. According to another aspect of the invention, an operator can change the idle throttle rate from the default rate to an alternate, user-provided idle throttle rate. Accordingly, the ECU is programmable, and includes an operator interface via which the operator can specify either or both of an alternate forward idle throttle value and an alternate forward idle throttle value. The alternate gear idle throttle rates are expressed as a percentage of the default idle throttle. To change the idle throttle from the default value to the user-specified value, the operator moves the control handle into a gear idle position and then inputs a neutral command via a command input device. In alternate idle throttle mode, the ECU sets the idle throttle to the user specified percentage of throttle, rather than to the default idle throttle. While the system is in alternate idle throttle mode, the ECU will disregard any movement of the control handle within the gear.
The sensitivity of the control handle is a function of the engine throttle range that corresponds to the forward throttle operating range of the control arm. According to another aspect of the invention, to increase the sensitivity of the control arm, the control system enables the operator to select an alternate range of throttle that is less than the default range. In alternate throttle mode, the operator is required to move the control arm a greater distance along its operational range to change engine throttle the same amount as in ordinary throttle mode. Thus, the sensitivity of the control arm can be increased, thereby providing the operator with more control over changes in throttle.
According to another aspect of the invention, the control system enables the operator to control a plurality of power trains (i.e., engine/transmission pairs) using a single control lever. Preferably, the control system enables the operator to control both port and starboard power trains via a single, master control lever. Thus, in contrast to known systems, a control system according to the invention provides for synchronized control of a plurality of engines in forward, neutral, and reverse.
To control the positions of the plurality of throttle actuator rods, a control system according to the invention preferably includes a multi-stage engine synchronization algorithm designed to provide the slave engine with smooth responses to changes in the master engine""s throttle. In a first stage of the multi-stage engine synchronization algorithm, lever synchronization, the system provides the slave engine with a throttle value based on the percent throttle of the master engine. That is, the master ECU determines the current percent of throttle based on the current position of the master control arm. The master ECU communicates its current percent of throttle to the slave ECU, which, in turn, commands the slave engine to achieve the same percent of throttle. In a second stage of synchronization, tach sync, a fine adjustment is made to engine throttle by comparing tachometric data from the engines. When the master and slave engines are within a predefined rate tolerance engine sync is considered to be complete.
It is well known that the amount of force an actuator needs to move its associated actuator rod from a first position to a second position varies from vessel to vessel, and even from engine to engine. According to another aspect of the invention, the control system includes a dynamic calibration or tuning capability so that the manufacturer and installer need not calibrate the system manually for each installation.
The ECU varies the amount of power it provides to the actuator""s motor based on historical data it maintains about the amount of power the actuator needs to move its actuator rod a certain distance in a certain amount of time. The ECU calculates the current needed to drive the actuator""s motor using the well known proportional integral derivative (PID) parameters, which provide a standard way to control the actuator servo. The ECU has a priori knowledge of how long the actuator should be expected to take to move the rod a certain distance.
While the actuator is moving the rod into place, the dynamic tuning process monitors how quickly the rod is actually moving. If the process determines that more or less force is necessary to move the rod into position in the expected amount of time, then the processor causes the actuator to apply more or less power to achieve the target. Each time the ECU controls the position of an actuator rod, it updates the parameters in a dynamic tuning table. The next time it needs to move the rod, it retrieves the data from the table and uses the data to calculate current for the next move. In this way, as system components degrade, the ECU automatically adjusts the amount of power it uses to move the rod.